Any research center dedicated to stimulating, facilitating, and advancing a scientific program must be armed with the best tools to create, collect, weigh, and interpret evidence. In this regard, epidemiological, clinical and basic science studies in environmental health science usually require guidance in study design, data management and statistical analysis. The Biostatistics, Epidemiology, and Data Management (BEDM) Core will provide an interrelated network of talented specialists to be used as a resource by the community of NIEHS Center researchers. BEDM Core members will provide consultative, programming, and analytical expertise in study design, execution, data management and statistical analysis to NIEHS Center investigators and to pilot study investigators who are planning or conducting research through the Center. The specific aims of the BEDM core are: 1. To aid investigators in the planning of and preparation for their center-related research, by consulting on epidemiologic, statistical and data management issues. From an epidemiological perspective, this includes consultation on the appropriate study design, data collection instruments, issues related to the identification and measurement of exposure, outcome and potentially confounding variables, and the issues of bias. From a statistical perspective this includes planning for approprate sample size and a priori identification of data analytic methods, consultation on the design of datacollection instruments and the appropriate media for data storage. 2. To aid investigators in the execution of their center-related research, by providing data-management services. The services include advice on interviewer training, data editing, data management software, analysis software, and computer hardware; the creation of computer databases and database interface systems; and trouble shooting for data management problems which may arise during the course of a study. 3. To aid investigators in the analysis of the data for center-related research, by consulting on epidemiological and statistical issues. Such consultations range from advice on design and statistical tests for animal and epidemiologic studies to sophisticated multivariate regression models such as Poisson, proportional hazards, and polychotomous logistic regression. Consultations will also be provided for methods for advanced statistical analysis, including the development of new statistical models, if required. Consultation on various methods of correction for measurement error will be provided. Finally consultation regarding inference will be provided.